Butyrate—CoA ligase explained

Butyrate—CoA ligase
Ec Number:	6.2.1.2
Cas Number:	9080-51-7
Go Code:	0047760

Butyrate—CoA ligase, also known as xenobiotic/medium-chain fatty acid-ligase (XM-ligase), is an enzyme that catalyzes the chemical reaction:

ATP + a carboxylic acid + CoA

\rightleftharpoons AMP + diphosphate + an acyl-CoA

The 3 substrates of this enzyme are ATP, carboxylic acid, and CoA, whereas its 3 products are AMP, diphosphate, and acyl-CoA.

This enzyme belongs to the family of ligases, specifically those forming carbon-sulfur bonds as acid-thiol ligases. This enzyme participates in the glycine conjugation of xenobiotics^[1] and butanoate metabolism.

Nomenclature

The systematic name of this enzyme class is butanoate:CoA ligase (AMP-forming). Other names in common use include:

• butyryl-CoA synthetase, fatty acid thiokinase (medium chain),
• acyl-activating enzyme, fatty acid elongate,
• fatty acid activating enzyme,
• fatty acyl coenzyme A synthetase,
• medium chain acyl-CoA synthetase,
• butyryl-coenzyme A synthetase,
• L-(+)-3-hydroxybutyryl CoA ligase,
• xenobiotic/medium-chain fatty acid ligase, and
• short-chain acyl-CoA synthetase.

Human proteins containing this domain

• ACSM1
• ACSM2A
• ACSM2B
• ACSM3
• ACSM4
• ACSM5
• ACSM6

References

• Mahler HR, Wakil SJ, Bock RM . 1953 . Studies on fatty acid oxidation. I. Enzymatic activation of fatty acids . J. Biol. Chem. . 204 . 453 - 68 . 13084616 . 1 .
• Massaro EJ . Lennarz WJ . 1965 . The partial purification and characterization of a bacterial fatty acyl coenzyme A synthetase . Biochemistry . 4 . 85 - 90 . 10.1021/bi00877a015 . 14285249.
• Websterlt JR, Gerowin LD, Rakita L . 1965 . Purification and characteristics of a butyryl coenzyme A synthetase from bovine heart mitochondria . J. Biol. Chem. . 240 . 29 - 33 . 14253428.

Notes and References

1. Badenhorst CP, van der Sluis R, Erasmus E, van Dijk AA . Glycine conjugation: importance in metabolism, the role of glycine N-acyltransferase, and factors that influence interindividual variation . Expert Opinion on Drug Metabolism & Toxicology . 9 . 9 . 1139–1153 . September 2013 . 23650932 . 10.1517/17425255.2013.796929 . Glycine conjugation of mitochondrial acyl-CoAs, catalyzed by glycine N-acyltransferase (GLYAT, E.C. 2.3.1.13), is an important metabolic pathway responsible for maintaining adequate levels of free coenzyme A (CoASH). However, because of the small number of pharmaceutical drugs that are conjugated to glycine, the pathway has not yet been characterized in detail. Here, we review the causes and possible consequences of interindividual variation in the glycine conjugation pathway. ...
   Figure 1. Glycine conjugation of benzoic acid. The glycine conjugation pathway consists of two steps. First benzoate is ligated to CoASH to form the high-energy benzoyl-CoA thioester. This reaction is catalyzed by the HXM-A and HXM-B medium-chain acid:CoA ligases and requires energy in the form of ATP. ... The benzoyl-CoA is then conjugated to glycine by GLYAT to form hippuric acid, releasing CoASH. In addition to the factors listed in the boxes, the levels of ATP, CoASH, and glycine may influence the overall rate of the glycine conjugation pathway..